This application is the U.S. National Phase of PCT/JP2017/007360 filed Feb. 27, 2017, which claims priority form JP 2016-050898 filed Mar. 15, 2016, the entire disclosure of which is incorporated herein by reference.
The present disclosure relates to a power source device, and particularly to an onboard power source device that includes a plurality of batteries.
For an onboard power source device, a technique is known in which a second battery is mounted in addition to a lead battery that has often been used conventionally. The second battery is charged with regenerative energy of the vehicle, and supplies the regenerative energy to an electric load (hereinafter referred to simply as “load”, and a plurality of loads will be referred to as “load group”) mounted on the vehicle. This technique is advantageous in improving fuel economy.
For example, a technique is known in which a connection switch is provided between two batteries so as to connect and disconnect the two batteries. By turning off the connection switch, the load is driven by only one of the batteries (i.e., the second battery described above), and thus efficient use of energy can be achieved. By turning on the connection switch, electric power can be supplied to the load even if one of the batteries fails (hereinafter, also referred to as “power supply”). That is, this power supply configuration has redundancy. An example of this technique is disclosed in JP2014-34288 A.